majiayu000 Resistor Similarity Calculator Skill
Guidance for working with ResistorSimilarityCalculator in the lib-electronic-components library.
For metadata-driven similarity architecture, see /similarity-metadata:
- SpecImportance levels (CRITICAL, HIGH, MEDIUM, LOW, OPTIONAL)
- ToleranceRule types (exactMatch, percentageTolerance, minimumRequired, etc.)
- SimilarityProfile contexts (DESIGN_PHASE, REPLACEMENT, COST_OPTIMIZATION, etc.)
- Calculator integration patterns and gotchas
Overview
The ResistorSimilarityCalculator compares resistors based on:
- Package size (0.3 weight) - 0402, 0603, 0805, etc.
- Resistance value (0.5 weight) - 10K, 100R, 4.7K, etc.
Maximum similarity is 0.8 (not 1.0) since tolerance and other specs aren't always extractable.
Applicable Types
ComponentType.RESISTOR
ComponentType.RESISTOR_CHIP_VISHAY
ComponentType.RESISTOR_CHIP_YAGEO
ComponentType.RESISTOR_CHIP_PANASONIC
ComponentType.RESISTOR_CHIP_BOURNS
// Any type starting with "RESISTOR_"
Similarity Scoring
| Condition | Score |
|---|---|
| Same value, same package | 0.8 |
| Same value, different package | 0.5 |
| Same package, different value | 0.3 |
| Different value, different package | 0.0 |
Value Extraction
The calculator extracts resistance values from MPNs:
| MPN | Extracted Value |
|---|---|
CRCW060310K0FKEA |
10K (10kΩ) |
RC0603FR-0710KL |
10K (10kΩ) |
ERJ3GEYJ103V |
10K (103 = 10×10³) |
Package Size Extraction
Common package codes in MPNs:
| Pattern | Package |
|---|---|
0603 |
0603 (1608 metric) |
0805 |
0805 (2012 metric) |
1206 |
1206 (3216 metric) |
Cross-Manufacturer Matching
The calculator can match equivalent resistors across manufacturers:
// Vishay 0603 10K vs Yageo 0603 10K
calculator.calculateSimilarity("CRCW060310K0FKEA", "RC0603FR-0710KL", registry);
// Returns >= 0.5 (both are 10K, may have same package)
Test Examples
// Same Vishay resistor - max similarity
calculator.calculateSimilarity("CRCW060310K0FKEA", "CRCW060310K0FKEA", registry);
// Returns 0.8
// Same value, different package
calculator.calculateSimilarity("CRCW060310K0FKEA", "CRCW080510K0FKEA", registry);
// Returns 0.5
// Same package, different value
calculator.calculateSimilarity("CRCW0603100RFKEA", "CRCW060310K0FKEA", registry);
// Returns 0.3 (100R vs 10K)
Implementation Notes
- Returns 0.0 for null MPNs or null registry
- Returns 0.0 for empty strings
- Handles unrecognized formats gracefully (returns 0.0-1.0)
Learnings & Quirks
Value Notation
- E96 notation:
103= 10×10³ = 10kΩ,4R7= 4.7Ω - Yageo TCR code
-07is NOT a separator, it's temperature coefficient
Package Extraction
- Some MPNs embed package in series name (e.g.,
RC0603) - Others have separate position (e.g.,
CRCW+0603)